Enhance device management and model handling in SnapForm

- Updated frame extraction logic to allow for single frame extraction.
- Integrated model readiness checks for BEN2 and DA3 models in relevant operators.
- Added directory name attribute to model specifications for better organization.
- Improved device selection logic for production and debug tasks.
- Refactored preferences to expose device settings and ensure they reflect available hardware.
- Enhanced runtime device detection and management, including support for CUDA and MPS.
- Updated tests to cover new device management features and model directory handling.
- Removed deprecated download model tests to streamline codebase.

src/snapform/models.py

@@ -5,6 +5,7 @@ from dataclasses import dataclass
 class ModelSpec:
     key: str
     label: str
+    directory_name: str
     repository: str
     license_name: str
     description: str
@@ -16,6 +17,7 @@ MODELS = {
     "SMALL": ModelSpec(
         key="SMALL",
         label="DA3 Small",
+        directory_name="da3_small",
         repository="depth-anything/DA3-SMALL",
         license_name="Apache 2.0",
         description="Fastest any-view model with Apache 2.0 weights",
@@ -24,6 +26,7 @@ MODELS = {
     "BASE": ModelSpec(
         key="BASE",
         label="DA3 Base",
+        directory_name="da3_base",
         repository="depth-anything/DA3-BASE",
         license_name="Apache 2.0",
         description="Balanced any-view model with Apache 2.0 weights",
@@ -32,6 +35,7 @@ MODELS = {
     "LARGE_1_1": ModelSpec(
         key="LARGE_1_1",
         label="DA3 Large 1.1",
+        directory_name="da3_large_1_1",
         repository="depth-anything/DA3-LARGE-1.1",
         license_name="CC BY-NC 4.0",
         description="Higher quality non-commercial model with larger VRAM use",
@@ -40,6 +44,7 @@ MODELS = {
     "GIANT_1_1": ModelSpec(
         key="GIANT_1_1",
         label="DA3 Giant 1.1",
+        directory_name="da3_giant_1_1",
         repository="depth-anything/DA3-GIANT-1.1",
         license_name="CC BY-NC 4.0",
         description="Non-commercial Giant model with Gaussian head",
@@ -48,6 +53,7 @@ MODELS = {
     "NESTED_GIANT_LARGE_1_1": ModelSpec(
         key="NESTED_GIANT_LARGE_1_1",
         label="DA3 Nested Giant Large 1.1",
+        directory_name="da3_nested_giant_large_1_1",
         repository="depth-anything/DA3NESTED-GIANT-LARGE-1.1",
         license_name="CC BY-NC 4.0",
         description="Non-commercial nested model with metric depth and Gaussian head",
@@ -58,6 +64,7 @@ MODELS = {
 BEN2_MODEL = ModelSpec(
     key="BEN2_BASE",
     label="BEN2 Base",
+    directory_name="ben2_base",
     repository="PramaLLC/BEN2",
     license_name="MIT",
     description="Fast high-quality background removal model",
@@ -142,3 +149,8 @@ def get_downloadable_model(model_key):
         return DOWNLOADABLE_MODELS[model_key]
     except KeyError as error:
         raise ValueError(f"Unknown model: {model_key}") from error
+
+
+def model_directory_name(model_key):
+    """Return the model's folder name inside the shared models directory."""
+    return get_downloadable_model(model_key).directory_name